Hello
I have built a SK450 with NTM Prop Drive Series 28-26A 1200kv / 250w and TURNIGY Plush 25amp Speed Controller .When a Turnigy 2650 mAh, 4S is used, the SK begins to oscillate and jumpy. Using Turnigy 3300mAh, 3S works just fine.
Does anybody have an explanation to this phenomena?
Thanks
Hillik
Replies
Sorry just presumed you were on APM.
My kk boards are the first gen ones they just have pots on then - i just turn each one about 20% ccw to reduce the roll and pitch gains, and yaw if the tail is wagging. i think they are more sophiscated now though - I'd start by reducing P on roll and pitch axis. However that is done (lcd?)
Simply put - reduce your gains on roll and pitch!
You are putting more volts through, so your motors are more powerful, but you are now pushing your control tuning - the apm now has more volts to play with when correcting any attitude error, so it will tend to over-shoot and wobble.
You will need to reduce stab_P to about 3.0, and reduce rate_p to about 0.085. This should not have any osciallations, but maybe a little vague in the air, (if it does reduce further. Tune up slowly from here till you are happy.
You might find you need to reduce rate_D a bit too, but that's less likely.